Same name but different materials reveal the truth about LED backlight LCD

LED backlight LCD TV becomes the main player in the market

In the field of flat-panel TVs, LCD TVs equipped with LED backlights have gradually become well-known to the public since 2009, and have become a new trend in the development of LCD TVs with their advantages in energy saving, environmental protection and color performance. By the Spring Festival of 2011, according to the latest statistics from ZDC, the proportion of attention paid to LCD TVs with LED backlights has exceeded that of traditional LCD TVs with CCFL backlights, reaching 51.5%. By the end of 2011, LCD TVs with LED backlights will truly become the protagonists of the Chinese LCD TV market.

The proportion of attention paid to different backlight products in the Chinese LCD TV market during the 2011 Spring Festival:

LED-backlit LCD TVs are not a new type of TV

LED backlight LCD TVs are mostly referred to as "LED TVs" by merchants and consumers in the market. Many consumers believe that "LED TVs" are a new type of TV, but this is not the case.

In fact, "LED TV" is just a replacement of the CCFL backlight of ordinary LCD TV with LED backlight. It should be more correctly called "LED backlight LCD TV" rather than a TV product that completely adopts the new display technology principle.

More high-end OLED TV

Friends who pay attention to the consumer electronics industry may often hear the term "OLED TV". Although it is only one letter different from "LED TV", "OLED TV" is a new TV technology that uses the principle of active light emission. Due to technical limitations, it is not widely used in home TVs.

Both are LED backlight LCD TVs, what are the differences?

Almost all brands on the market have launched LCD TVs with LED backlights, so are they all the same? The answer is: no.

In the early days of LED backlight LCD TVs, many products were equipped with white LED backlights, which replaced the original CCFL fluorescent tubes with LED light sources that can only emit white light. As technology develops, RGB-LED backlights have begun to be used on TVs. They are made of mixed red, green and blue light, and have better color gamut performance than white LED backlights.

There are also many differences in LED backlight sources

Of course, in addition to the differences in the LED lights themselves, the incident position of the LED backlight source is also different, which can be divided into two categories: direct-down and side-entry.

Let's talk about the side-entry LED backlight first. It places the light source on the side of the light guide plate. The specially designed light guide plate allows the light to be evenly dispersed on the entire plane. It uses fewer LEDs and the body can be designed to be very thin. For example, the ZX1 launched by Sony previously has a 40-inch body thickness of less than 1 cm.

However, edge-entry LED backlights also have their own disadvantages, such as low light utilization, poorer uniformity compared to direct-type, and inability to perform regional control.

How the two projection positions work

Direct-lit LED backlights do not require a light guide plate. The LED array is placed at the bottom of the light box. The light emitted by the LED is reflected by the bottom and sides, and then evenly emitted through the diffuser and optical module on the surface. Compared with side light sources, direct-lit LED backlights can dynamically control the backlight, so that when displaying images of certain dark scenes, only the local lighting of the necessary backlight area (which appears as black or darker parts on the screen) needs to be adjusted to display high-quality image effects with natural light and dark contrast.

However, direct-type LED backlights are more expensive and are generally only available on high-end models. They are also larger in size, and the body cannot be as thin as LCD TVs that use edge-type LED backlights.

Among direct-lit LED backlight sources, a new product called "FULL LED backlight" was launched in 2010. It uses more LED lights and can control more areas, so the response to changes in a certain area is faster and more accurate.

Of course, you may ask whether more LED lights will increase power consumption? In fact, although there are more direct-type LED backlights, the light utilization rate is high. In the actual test process, we can see that the energy-saving effect is also very good.